5.7 TBI w/4l80 surging on deceleration

Hello all,

My issue is when decelerating, my motor surges +/- a few hundred rpm. It's like someone it pulsing the brakes. I use WINALDL and have a MSD trans controller and nothing looks abnormal.
My first thought was the convertor locking and unlocking or the IAC controller going crazy but nothing shows up when data logging.

Has anyone experienced anything like this. My motor is basic, 9.5/1, small lunati cam, header, etc. I am running a OEM small block 4l80 convertor.
I do not believe vacuum is the issue, I have ~18 at idle and this problem was not there months ago.

All help is greatly appreciated.
Chris